As mobile communication network technology evolves, and higher capability networks and systems become available, the mobile radio communications devices employed such as known Mobile Equipment (ME) and User Equipment (UE) tend to retain capabilities for different Radio Access Technologies (RAT) and so allow for handover procedures both on an inter-RAT and intra-RAT basis.
A high degree of security and integrity is an ongoing requirement for mobile communications networks and it is particularly desirable to seek to prevent interception of communications messages.
Security measures often currently employ keys such as a Ciphering Key (CK) and an Integrity Key (IK) and the generation of such keys often occurs during handover procedures.
It is noted that limitations and disadvantages exist in the operation and management of such security issues and that can lead to a potential compromise in security.
Known procedures for the generation and management of security keys are disclosed in United States Patent Application, Publication Nos. 2009/161874 A1, and 2009/154703 A1, Canadian Patent Application No. 2659959 A1 and U.S. Pat. No. 7,519,178 B1, which offer quite different solutions to the problem of security and enhancement as compared with the present invention.